Firing mechanism



Jy 13, 1948. G. B. DAvls, JR., Erm. 4,920

V FIRING MEcHANIsM Filed Jan. 13, 1947 3 Sheets-Sheet 1 EEQIBE .BIluvis, *T TI- PLI 1.51111: RRusarlkI-mntz JUE? my w48 G. B. DAvls, JR,ETAL 2,444,920

FIRING MECHANISM Filed Jan. 15, 1947 3 Sheets-Sheet 2 'July' 13 l948; G.B. DAvls, JR., TAL; 2,444,920

IRI'NG MEGHANISM 3 Sheets-Sheet 3 Filed Jan. 13, 1947 Patented July 13,1948 FIRIN G MECHANISM George B. Davis, Jr., Washington,

D. C., and

Isaac F. Rosenkrantz, Greenbelt, Md. Application January 13, 1947,Serial No. 721,831

8 Claims.

(Granted under the act of March amended April 30, 1928; 370 0.

The invention described in the foregoing specication and claims may bemanufactured and used by or for the Government for governmental purposeswithout the payment to us of any royalty thereon.

This invention relates to improvements in firing mechanism for guns, andparticularly mortars.

An object of the invention is to provide selective means whereby afiring pin may be extended for drop firing and retracted for handfiring.

Another object of the invention is to provide a firing mechanism whereinthe firing pin may be projected into the rear end of the gun barrel andheld in position to detonate a primer in the base of `a round, when theround gravitates into firing position.

Another object of the invention is to provide a iiring mechanism whereinthe firing pin may be retracted and held against the influence of acompressed firing spring and released at a desired time.

A further object of the invention is to provide positive cam-operatedmeans for selectively retracting or projecting the firing pin at thewill of an operator.

A further object of the invention is to provide an emergency stopextension on the firing pin holder to prevent breakage of the movingparts, if excessive blow-back pressure is developed in the gun barrel.

A still further object of the invention is to provide a retractor springon the firing pin whose bias is so proportioned to the bias of the ringspring, that the iiring pin is caused to normally assume a partlyretracted or neutral position.

A still further object of the invention is to provide closure meanscarried by the ring pin for preventing propellent gases from reachingthe firing mechanism.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings, forming a part of this specification, andin which like numerals are employed to designate like parts throughoutthe same,

Figure 1 is an elevational view of a mortar barrel equipped with thepresent invention,

Figure 2 is a longitudinal on the line 2 2 of Figure 1,

Figure 3 is a transverse sectional view of Figure 2 taken on the line 33,

Figure 4 is a similar view taken on the line 4 4 of Figure 2,

sectional view taken 3, 1883, as G. 757) 2 Figure 5 is a similar viewtaken on the line 5-5 of Figure 2,

Figure 6 is a longitudinal sectional View taken on the line 6-6 ofFigure 2 and showing parts in elevation,

Figure 6a is a development illustrating the relationship of the cookingpin, its slot and the cooperating cams in neutral position,

Figure 7 is a View similar to Figure 6 showing the firing pin in cockedposition,

Figure 7a is a development illustrating the relationship of the cookingpin, its slot and the cooperating cams in cocked position,

Figure 8 is a view similar to Figure 6 showing the parts in nredposition,

Figure 8a is a development illustrating the relationship of the cookingpin, its slot and the cooperating cams in red position,

Figure 9 is a view similar to Figure 6 showing the firing pin locked inits forward position, and,

Figure 9a is a development illustrating the relationship of the cookingpin, its slot and the cooperating cams in the forward position of. thefiring pin.

In the drawings, wherein for the purpose'of illustration, is shown apreferred embodiment of the invention, the reference character Bindicates a barrel for guiding a projectile.

A breech closure I0 of cup-like formation is screw-threadedly connectedto the barrel Bat its forward end, and has a rearwardly extendingportion I I. The portion II is bored and screwthreaded at I2 to receivethe forward screwf threaded end of a tubular housing i3.

Formed in the breech closure l0 is a partition I4 having a forwardlyextending boss I5 centrally of its forward face, for limiting therearward movement of an inserted round (not shown).

Concentric with the longitudinal axis of the breach closure Il] andextending throughthe boss I5 is a bore I5, formed to slidably receivethe reduced forward end I1 of a firing pin I8.

The tubular housing I3 is provided :with a central longitudinal bore I9concentric with the bore I6 in the boss I5. Slidable and oscillatable inthe bore I9 is a cylindrical ringpin holder 26 secured to the rear endof the firing pin IB'by a pin 2l. The rear end of the bore I9 is closedby a wall 22 between which and the rearv end of the firing pin holder2l) a firing spring 23 is compressed.

Emergency stop means in the form of a rod 24, secured to the rear end ofthe ring pin holder 20, abuts the end wall 22 if excessive 3 blow-backpressure is developed in the gun barrel B.

The forward end of the bore I9 is counterbored as at 25 to form a seatfor a sleeve 2B which acts as a stop shoulder for a collar 2lsurrounding firing pin: I8; A retractor spring 28 surrounds the firingpin I8 and is confined between the forward end of the firing pin holder23 and the collar 21.

A cylindrical enlargement 23 formed on the firing pin I8 slides Withinthe sleeve 23, and when the gun is fired, abuts the rear surface `of thepartition I4 adjacent the bore I3. The en largement 29 also serves as aclosure for the bore I6 to prevent propellent gases from entering thebore I9 and destroying the springs 23 and'28.

A stud 30 is secured to the firing pin holder 23 and extends radiallytherefrom throughA a longitudinal slot 3I in the tubular housing I3. Thelongitudinal slot 3I has oppositely extending circumferential branches32 and 33.

Rotatably mounted exteriorly of the tubular housing .I3 is a sleeve 34having an internal annular groove 35 for receiving the outer end of theradially extending stud 3l). The sleeve 34 is restrained" againstlongitudinal movement by the rear portion I.I of the breech closure andby a stop enlargement 36 formed on the tubular'housing I3; The annulargroove 35 is formedlwith a longitudinalpassageway.31 to facilitateassembly, and. circumferentiall'y extending enlargements includingcarnsurfacesl 3S and39. One wall 4l) ofthe passage-way 3T is'L extendedforwardly and serves as a firing means` when the stud 33 is seated inthe branch 32 of slot 3I, and the sleeve 34`1isrotated in acounter-clockwise direction;

After a round is` fired the sleeve 34 may be rotated in a clock-wise.direction at which time the cam surface 38 will contact the stud 30 andreturnit to' itsfcocked position in the branch 32 of" the' slot 3l;

"When the" firing pinis in neutral position and it'is" desired to changeto drop re the sleevev 34 is rotated in counter-clockwise direction,forcing the'carnl surface 39 against the` stud 3B and seating it" in thebranch 33 Yof the longitudinal slot 3|". Thisroperation will hold theforward end I'I of the'ring-pin inanextended Iposition within thebasecap.

Suitable indicia 4I isA impressed on the outer circumference ofthesleeve 34 adjacent the'stop 361' A pointer' 42 on the stop 3Sregisters with the'indicia 4'I- when the sleeve 34 is rotated to clearlyindicate the position of the firing mechanism;

A-spring pressed detent 43 locks the tubular housing-I3 to the rearportion II of the'. breech -closurelll The reduced tang of the detentprojectsiradially outwardlof the breech closure and is ttedwith a ring,44 for easy withdrawalof the detentV from its locked position.

The: operation of the iringl mechanism is as follows:

Figureswl, 6 and 6a show the mechanism in a neutralizor safety position.The bias of the retractor` spring` 28 resists the bias of the ringspring suiciently to keep the firing pin holder andfits: stud 30`in theposition shown. The forward end' I-'I of the firing pin I8 is` safelyretracted withinthebore I5 in the partition I4.

When it is desired to use the gun it is only necessary to-observe thepresent position of the indicia14-I and pointer 42, to determine inwhich direction to rotate the sleeve 34.

If the mechanism is found to be in neutral position, as shown in Figures6 and 6a, and it is desired to operate the gun as a hand fired Weapon,the sleeve 34 is rotated clockwise as viewed from the rear of the gun.This movement of the sleeve causes the cam surface 38 to bear on thestud 30 and'y retract it in the slot 31| until? the stud is seated inthebranch 32' of the Isaid slot, as shown in Figures 7 and 7a.

The firing mechanism is cocked by the above described movement of thesleeve 34 and cam 38, and when a round of ammunition (not shown) isplaced: inthe-barrel, the weapon is ready to be fired.'

Counter-clockwise movement of the sleeve 34 will cause the wall 40 ofthe passageway 31 to bear' against the stud 30, forcing it out of thebranch. slot 32 and. into the slot Si. The firing pin holder ll-,is'thenfree to move forward under the bias of the firing spring 23 and forcethe ring pin through. the bore I5 of the partition I4 into operative.position, as shown in Figures 8 and. 8a.v

Figure. 8. shows the, positionof the mechanism at the instant of ring.It will be seen in this figure that thepassage of propellent gases fromthewbarrel is' prevented by the enlargement 29 on the ri'ng pin abuttingthe rear face of the partition I4 and sealing the bore IE.

After the force fof` the firing stroke has subsided in the firing pinandholder 23,. the retractor spring` 28=recovers and returnsthemechanismto neutral position as shown in Figure 6. Ify desired the weaponmay becocked again by the method above described.

If it is desired to set the weaponfor drop fire, as shown in Figures 9and 9a, counter-clockwise movement is imparted to the sleeve 34. As hasbeen described, the `ring-v mechanism is normally infneutral-positionsothateither methodof fire may becluicklyl selectedby the simple operationof rotating the sleeve 34.

When the sleeve issrotated counter-clockwise the Ycam surface ofl thegroove 35 bears against the studl 30;,forcing' it forwardly to projectthe firing pin -end I'I into the barrel. The stud 3Bis'also-forcedintofthe branch 330i. the slot 3| Where-it remains to lockthe firingV pin in operative position for `drop fire;

It is tobe understood that the form of the invention, herewith shown anddescribed, is to be taken asa preferred example of the same, and thatvarious changes in the shape, size and arrangement of' parts-may beresorted to, without departing` from the spirit of the invention, or thescope ofI the subjoinedY claims.

We claim:r

1. A gun firing mechanism comprising, a breechr closure having anaperturetherein, a generally tubular housing threadedly engagedl withsaidA closureincluding, a. longitudinal slot in the outer peripherythereof having oppositely extending circumferential branches adjacent toits opposite ends, a. ring pin and holder secured togetherfor-jointreciprocation within said housing, a firing springmounted forcompression between said holder and an end Wall of said housing,vemergency stop means on saidr holder, shoulder means in saidlhousing,abutment means on said firing `pin slidable Within said shoulder means,a collar slidably mounted on said. firing pin. and engageable with saidshoulder means, a retractor spring on saidrring, pin compressiblebetween said collar andv said holder for resiliently retaining saidfiring pin out of said. aperture, a stud projecting radially from saidholder through and slightly beyond said slot, and a sleeve rotatablymounted on the exterior of said housing including an internal annulargroove receiving said stud and defining a lplurality of cam surfacesengageable therewith, said mechanism be ing constructed and arrangedwhereby rotation of said sleeve in one direction is operative toposition said Stud in one of said branches compressing said firingspring and cooking said ring pin, and reverse rotation of said sleeve isoperative to release said stud from said one branch, continued reverserotation causing said stud to be seated in the other of said branchescompressing said retractor spring and extending said iiring pin throughsaid aperture.

2. A gun firing mechanism comprising, a breech closure having anaperture therein, a generally tubular housing threadedly engaged withsaid closure including a longitudinal slot in the outer peripherythereof having oppositely extending circumferential branches adjacent toits opposite ends, a firing pin and holder secured together Vfor jointreciprocation within said housing, a firing spring mounted forcompression between said holder and an end wall of said housing,shoulder means in said housing, abutment means on said firing pinslidable within said shoulder means, a collar slidab'ly mounted on saidiiring pin and engageable with said shoulder means, a retractor springon said firing pin compressible between said collar and said holder forresiliently retaining said firing pin out of said aperture, a studprojecting radially from said holder through and slightly beyond saidslot, and a sleeve rotatably mounted on the exterior of said housingincluding an internal annular groove receiv ing said stud and dening aplurality of cam surfaces engageable therewith, said mechanism beingconstructed and arranged whereby rotation of said sleeve in onedirection is operative to position said stud in one of said branchescompressing said firing spring and cooking said ring pin, and reverserotation of said sleeve is operative to release said stud from said onebranch, continued reverse rotation causing said stud to be seated in theother of said branches compressing said retractor spring and extendingsaid firing pin through said aperture.

3. A gun firing mechanism comprising, a breech closure having anaperture therein, a housing engaged with said closure including alongitudinal slot in the outer periphery thereof having oppositelyextending circumferential branches ad jacent to its opposite ends, aring pin reciprocable within said housing, a firing spring urging saidfiring pin toward said aperture, shoulder means in said housing,abutment means on said firing pin, a collar slidably mounted on saidring pin and engageable with said shoulder means, a retractor spring onsaid firing pin, a stud connected to said firing pin and projectingthrough and slightly beyond said slot, and a sleeve rotatably mounted onthe exterior of said housing including an internal annular groovereceiving said stud and defining a plurality of cam surfaces engageabletherewith, said mechanism being constructed and arranged wherebyrotation of said sleeve in one direction is operative te position saidstud in one of said branches compressing said firing spring and cookingsaid rn ing pin, and reverse rotation of said sleeve is operative torelease said stud from said one branch, continued reverse rotationcausing said stud to be seated in the other of said branches dcompressing said retractor spring and extending said firing pin throughsaid aperture.

4. A gun firing mechanism comprising, a breech closure having anaperture therein, a housing engaged with said closure including alongitudinal slot in the outer periphery thereof having offse branchesadjacent to its opposite ends, a firing pin reciprocable within saidhousing, a nring spring urging said firing pin toward said aperture,means for resiliently retaining said iiring pin out of said aperture, astud connected to said ring pin and projecting through and slightly:beyond said slot, and a sleeve rotatably mounted on the exterior ofsaid housing including an internal annular groove receiving said studand defining a plurality of cam surfaces engageable therewith, saidmechanism being constructed and arranged whereby rotation of said sleevein one direction is operative to position said stud in one of saidbranches compressing said ring spring and cooking said firing pin,reverse rotation of said sleeve causing said stud to be seated in theother of said branches and extending said firing pin through saidaperture.

5. A gun ring mechanism comprising, a breech closure having an aperturetherein, a housing attached to said closure and including means forminga longitudinal through slot therein having oifset branches extendingtherefrom, a iiring pin in said housing, a firing spring urging saidfiring pin toward said aperture, a stud connected to said ring pin andprojecting through and beyond said slot, and a sleeve enclosing saidslot including means forming a plurality of cam surfaces engageable withsaid stud and constructed and arranged whereby successive oppositerotation of said sleeve alternately positions said stud in each of saidbranches.

6. A gun ring mechanism comprising, a housing, means forming alongitudinal through slot in said housing having an oifset branchextending therefrom, a firing pin in said housing, a stud connected tosaid firing pin and projecting through and beyond said slot, and asleeve enclosing said slot including means forming a cam surfaceengageable with said stud and constructed and arranged whereby rotationof said sleeve positions said stud in said branch.

7. A gun ring mechanism comprising, a breech closure having an aperturetherein, a housing threadedly engaged with said closure, a firing pinreciprocable in said aperture, a holder` secured to said ring pin forjoint reciprocation within said housing, a firing spring mounted forcompression between said holder and an end wall of said housing,abutment means on said firing pin slidable within said housing intocontact with the said breech closure adjacent the said aperture toeffect a gas tight seal to prevent flow of propellent gas to the saidhousing, and means for cooking and releasing the ring pin.

8. A gun firing mechanism comprising a breech closure having an aperturetherein, a housing threadedly engaged with said closure, a :Firing pinreciprocable in said aperture, a holder secured to said iiring pin forjoint reciprocation within said housing, a firing spring mounted forcompression between said holder and an end wall oi said housing,abutment means on said firing pin to limit the forward movement of thefiring pin and seal the said aperture against passage of propellentgases to the said housing, and means for cooking and releasing thefiring pin.

GEORGE E. DAVIS, JR. ISAAC' F. ROSE-NKRANTZ.

